The AMS (a)H18 and H35 processes are two of the most promising candidates for HV-CMOS detectors. One issue are their low standard resistivity (10-20 Ohm*cm) and therefore small depletion layers before irradiation of only about 10-20um.
While this issue was addressed by using higher-resistivity substrates (up to 1 kOhm*cm) in dedicated runs, the behaviour of the standard substrate after irradiation is still of interest. Earlier studies have shown that due to the high acceptor concentration, acceptor removal is the main bulk effect of NIEL irradiation. At the same time, the removal rates differ by a large factor between irradiations with reactor neutrons and 24 GeV protons at CERN. Both particle types are not representative for the HL-LHC environment, which will be dominated by mininum bias events generating mainly pions with few 100 MeV of energy. To come closer to this energy regime, a selection of AMS-produced chips have been irradiated with 800 MeV protons at LANCSE up to a fluence of 1.3e16 neq/cm2.
First results from edge-TCT measurements on these samples will be presented and a comparison to earlier neutron- and 24-GeV-proton results will be shown before giving an outlook on the implications of these results.